2.4 Software construction

Introduction

The term software construction refers to the detailed creation of working, meaningful software through a combination of coding, verification, unit testing, integration testing, and debugging.

The software construction is linked to all the other software engineering, most strongly to software design and software testing. This is because the software construction process itself involves significant software design and test activity. It also uses the output of design and provides one of the inputs to testing, both design and testing being the activities. Detailed boundaries between design, construction, and testing (if any) will vary depending upon the software life cycle processes that are used in a project.

Although some detailed design may be performed prior to construction, much design work is performed within the construction activity itself. Thus the software construction is closely linked to the software design.

Throughout construction, software engineers both unit-test and integration-test their work. Thus, the software construction is closely linked to the software testing as well.

Software construction typically produces the highest volume of configuration items that need to be managed in a software project (source files, content, test cases, and so on). Thus, the software construction is also closely linked to the software configuration management.

Software construction fundamentals

The fundamentals of software construction include:

• Minimizing complexity
• Anticipating change
• Constructing for verification
• Standards in construction

The first three concepts apply to design as well as to construction. The following sections define these concepts and describe how they apply to construction.

Minimizing complexity

A major factor in how people convey intent to computers is the severely limited ability of people to hold complex structures and information in their working memories, especially over long periods of time. This leads to one of the strongest drivers in software construction: minimizing complexity. The need to reduce complexity applies to essentially every aspect of software construction, and is particularly critical to the process of verification and testing of software constructions.

In software construction, reduced complexity is achieved through emphasizing the creation of code that is simple and readable rather than clever.

Anticipating change

Most software will change over time, and the anticipation of change drives many aspects of software construction. Software is unavoidably part of changing external environments, and changes in those outside environments affect software in diverse ways.

Anticipating change is supported by many specific techniques:

• Communication methods (for example, standards for document formats and contents)
• Programming languages (for example, language standards for languages like Java and C++)
• Platforms (for example, programmer interface standards for operating system calls)
• Tools (for example, diagrammatic standards for notations like UML (Unified Modeling Language))